PaymentApp: Add interfaces for implementing InvokePaymentApp().

components/payments/payment_app.mojom

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module payments.mojom;
 
+import "components/payments/payment_request.mojom";
+import "url/mojo/url.mojom";
+
 enum PaymentAppManifestError {
   NONE,
   NOT_IMPLEMENTED,
   NO_ACTIVE_WORKER,
   MANIFEST_STORAGE_OPERATION_FAILED,
 };
 
 struct PaymentAppOption {
   string name;
   string? icon;
   string id;
   array<string> enabled_methods;
 };
 
 struct PaymentAppManifest {
   string name;
   string? icon;
   array<PaymentAppOption> options;
 };
 
 interface PaymentAppManager {
   Init(string service_worker_scope);
   SetManifest(PaymentAppManifest payment_app_manifest)
       => (PaymentAppManifestError error);
   GetManifest()
       => (PaymentAppManifest payment_app_manifest, PaymentAppManifestError error);
 };
+
+struct PaymentAppRequestData {
+  url.mojom.Url origin;
+  array<PaymentMethodData> methodData;
+  PaymentItem total;
+  array<PaymentDetailsModifier> modifiers;
+  string optionId;
+};